var data = [{
    price: 19.99999999
}, {
    price: 14.99999999
}, {
    price: 13.99999999
}];


function dealData(data) {
    for (const obj in data) {
        console.log(data[obj].price);
        data[obj].price.toFixed(2);
        console.log(data[obj].price.toFixed(2));
    }
    return data;
};

var res = dealData(data);
console.log(res);